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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 | /* * linux/fs/proc/base.c * * Copyright (C) 1991, 1992 Linus Torvalds * * proc base directory handling functions */ #include <asm/segment.h> #include <linux/errno.h> #include <linux/sched.h> #include <linux/proc_fs.h> #include <linux/stat.h> static int proc_readbase(struct inode *, struct file *, struct dirent *, int); static int proc_lookupbase(struct inode *,const char *,int,struct inode **); static struct file_operations proc_base_operations = { NULL, /* lseek - default */ NULL, /* read - bad */ NULL, /* write - bad */ proc_readbase, /* readdir */ NULL, /* select - default */ NULL, /* ioctl - default */ NULL, /* mmap */ NULL, /* no special open code */ NULL, /* no special release code */ NULL /* can't fsync */ }; /* * proc directories can do almost nothing.. */ struct inode_operations proc_base_inode_operations = { &proc_base_operations, /* default base directory file-ops */ NULL, /* create */ proc_lookupbase, /* lookup */ NULL, /* link */ NULL, /* unlink */ NULL, /* symlink */ NULL, /* mkdir */ NULL, /* rmdir */ NULL, /* mknod */ NULL, /* rename */ NULL, /* readlink */ NULL, /* follow_link */ NULL, /* bmap */ NULL, /* truncate */ NULL /* permission */ }; static struct proc_dir_entry base_dir[] = { { PROC_PID_INO, 1, "." }, { PROC_ROOT_INO, 2, ".." }, { PROC_PID_MEM, 3, "mem" }, { PROC_PID_CWD, 3, "cwd" }, { PROC_PID_ROOT, 4, "root" }, { PROC_PID_EXE, 3, "exe" }, { PROC_PID_FD, 2, "fd" }, { PROC_PID_ENVIRON, 7, "environ" }, { PROC_PID_CMDLINE, 7, "cmdline" }, { PROC_PID_STAT, 4, "stat" }, { PROC_PID_STATM, 5, "statm" }, { PROC_PID_MAPS, 4, "maps" } }; #define NR_BASE_DIRENTRY ((sizeof (base_dir))/(sizeof (base_dir[0]))) int proc_match(int len,const char * name,struct proc_dir_entry * de) { if (!de || !de->low_ino) return 0; /* "" means "." ---> so paths like "/usr/lib//libc.a" work */ if (!len && (de->name[0]=='.') && (de->name[1]=='\0')) return 1; if (de->namelen != len) return 0; return !memcmp(name, de->name, len); } static int proc_lookupbase(struct inode * dir,const char * name, int len, struct inode ** result) { unsigned int pid, ino; int i; *result = NULL; if (!dir) return -ENOENT; if (!S_ISDIR(dir->i_mode)) { iput(dir); return -ENOENT; } ino = dir->i_ino; pid = ino >> 16; i = NR_BASE_DIRENTRY; while (i-- > 0 && !proc_match(len,name,base_dir+i)) /* nothing */; if (i < 0) { iput(dir); return -ENOENT; } if (base_dir[i].low_ino == 1) ino = 1; else ino = (pid << 16) + base_dir[i].low_ino; for (i = 0 ; i < NR_TASKS ; i++) if (task[i] && task[i]->pid == pid) break; if (!pid || i >= NR_TASKS) { iput(dir); return -ENOENT; } if (!(*result = iget(dir->i_sb,ino))) { iput(dir); return -ENOENT; } iput(dir); return 0; } static int proc_readbase(struct inode * inode, struct file * filp, struct dirent * dirent, int count) { struct proc_dir_entry * de; unsigned int pid, ino; int i,j; if (!inode || !S_ISDIR(inode->i_mode)) return -EBADF; ino = inode->i_ino; pid = ino >> 16; for (i = 0 ; i < NR_TASKS ; i++) if (task[i] && task[i]->pid == pid) break; if (!pid || i >= NR_TASKS) return 0; if (((unsigned) filp->f_pos) < NR_BASE_DIRENTRY) { de = base_dir + filp->f_pos; filp->f_pos++; i = de->namelen; ino = de->low_ino; if (ino != 1) ino |= (pid << 16); put_fs_long(ino, &dirent->d_ino); put_fs_word(i,&dirent->d_reclen); put_fs_byte(0,i+dirent->d_name); j = i; while (i--) put_fs_byte(de->name[i], i+dirent->d_name); return j; } return 0; } |